Pregnant and smoking cannabis

Patient: Will smoking cannebis once or twice a week harm my baby? I have quit smoking cigarettes and drinking alcohol. I take no other medication except for my pregnancy vitamines and has had a very good pregnancy so far. Just have the odd puff here and there when I return from work at night, i am a waittress, it works brilliant for my back ace etc. Could you please let me know, i am 28 weeks pregnant.

Doctor: I would strongly discourage you from smoking cannabis while pregnant. Research suggests women who smoke cannabis during pregnancy may stunt the growth of their babies. Regular users are more likely to give birth to small babies, also significantly shorter, and with smaller heads, compared to non-users. The effect of smoking one cannabis joint a week throughout pregnancy appears to be equivalent to the effect produced by smoking up to 15 cigarettes a day. The reason why cannabis retards growth is still unclear. Research has also shown that even moderate doses of cannabinoid compounds, when administered during the perinatal period, can have severe consequences for brain maturation, leading to long-lasting neurodevelopmental changes and neurobehavioural consequences.